posix-timers: Add cond_resched() to posix_timer_add() search loop

[ Upstream commit 5f2909c6cd13564a07ae692a95457f52295c4f22 ]

With a large number of POSIX timers the search for a valid ID might cause a
soft lockup on PREEMPT_NONE/VOLUNTARY kernels.

Add cond_resched() to the loop to prevent that.

[ tglx: Split out from Eric's series ]

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20250214135911.2037402-2-edumazet@google.com
Link: https://lore.kernel.org/all/20250308155623.635612865@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index b924f0f096fa4495e3fd1f0c8a3e02ab4eb1ccb2..7534069f6033345e4b1dd8f21834a4e6011a63d2 100644 (file)
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -118,6 +118,7 @@ static int posix_timer_add(struct k_itimer *timer)
                        return id;
                }
                spin_unlock(&hash_lock);
+               cond_resched();
        }
        /* POSIX return code when no timer ID could be allocated */
        return -EAGAIN;